Cutting tool



April 7, 1964 PARSTORFER 3,127,805

CUTTING TOOL Filed Aug. 15, 1960 l6 42 I V 56 i2 flq- ,nmmwl I0 [In 24 4ATTORNEY United States Patent Office 3,127,805 Patented Apr. 7, 19643,127,805 CUTTING TOOL John Parstorfer, Phiiadeiphia, Pa., assignor toBurroughs Corporation, Detroit, Mich, a corporation of Michigan FiledAug. 15, 1960, Ser. No. 49,633 8 Claims. ((31. 33-456) This inventionrelates to a cutting tool for parting or severing printed or etchedcircuit conductors and the like fixed or otherwise impressed on the faceof a panel. The invention was specially designed for, but is not limitedto, cutting printed circuit conductors on the contact panels disclosedand claimed in a copending application of John Parstorfer and Edgar O.Sprude, Serial No. 15,920, filed March 18, 1960, and assigned to thesame assignee as the present invention.

An object of the invention is to provide a cutting tool of theabove-described general character which is simple in construction, easyto use and inexpensive to manufacture.

Another object of the invention is to provide a cutting tool forsevering printed circuit conductors and the like and which will producea sharp, uniform cut through the conductor without tearing it or liftingit from its supporting panel.

Another object of the invention is to provide such a tool with means forclamping a printed circuit panel and the like, and with further meansfor assuring a predetermined clamping force on the panel.

A more specific object of the invention is to provide in such a tool, aclamping member of rigid, one-piece construction to best resist clampingand cutting forces yet so formed as to allow a hinge-like movement ofits operable part.

In accordance with the above objects and first briefly considered in itsbroad aspects, the invention comprises clamping members for holding aprinted circuit or the like panel and a movable cutting member operableto sever a conductor on the panel while the panel is in the clampedposition. The invention also contemplates the use of means for limitingrelative movement between the clamping members to assure that anoperator cannot use excessive clamping force on the panel. The-inventionalso contemplates the use of guiding means for the cutting member tocontrol it accurately throughout the cutting stroke, and gauge means forreadily locating a panel in cutting position in the too-l.

The invention will be more clearly understood when the followingdetailed description of the preferred embodiment thereof is read inconjunction with the accompanying drawings in which:

FIG. 1 shows an isometric view of a cutting tool constructed inaccordance with the invention, and a similar View of a fragment of acontact panel disclosed in the above-mentioned Parstorfer-Sprudeapplication having printed circuit conductors on one face thereof,certain of which have been severed by the illustrated tool, and aplurality of equally spaced knife contacts on the opposite face thereof;

FIG. 2 is a front elevation of the tool shown in FIG. 1 and showing thecontact panel in phantom view located in the tool preparatory to acutting or severing operation;

FIG. 3 is a vertical sectional view of the tool shown in FIG. 2 but withthe contact panel omitted;

FIG. 4 is an enlarged fragmentary end view of the tool;

FIG. 5 is an enlarged fragmentary illustration showing the cuttingaction of the cutting member; and

FIG. 6 is an enlarged view of a portion of the contact panel showing adiscontinuity cut in one of its printed circuit conductors.

Turning now to the drawings, the illustrated tool comprises a clampingbed or base 10, a clamping bar 12, a

toothed cutting blade 14 and a rock lever 16 movably mounted on theclamping bar 12 for actuating the cutting blade 14.

The base 10 is secured at one end to an end of the clamping bar 12, asby cap screws 18, and has at least one reduced area portion 20, in thisembodiment three, formed by one or more cross slots 21, which allows thefree end of the base it) to be moved elastically with a spring orhinge-like action, as will be explained. The base 10 is provided withgauging means for locating a panel transversely of the tool which in thepresent embodiment takes the form of a plurality of elongated slots 24for locating the particular contact panel 22 by its knife contacts 28.An adjustable stop gauge 26 is provided to locate the panel 22longitudinally of the tool and is secured in adjusted position to thebase 10 by means of a clamping screw 32.

The free end of the clamping bar 12 is formed with an upwardly extendingyoke 34 and a depending jaw 36 provided with a slot 33 for freelyguiding the lower portion of the cutting blade 14.

The rock lever 16 is provided with a slot 40 in which is press-fittedthe upper portion of the cutting blade 14 and is mounted on a pivot pin42 journalled at its end portions in the yoke 34 and passing through thecutting blade 14, the pivot pin 42 being held in the yoke 34 byretaining rings 43. The cutting blade 14 is secured further to the rockarm 16 by means of a dowel pin 44 passing through the blade andpress-fitted in the depending slotted arm 46 of the rock lever 16. Acompression spring 48 operating through the rock lever 16 normallymaintains the tooth 49 of the cutting blade 14 against the bottom 50 ofslot 38 in which position the cutting edge 52 of the blade tooth 49 isadjacent to the lands or faces 54 of jaw 36. The jaw faces 54 aresufficiently wide, pref erably wider than a conductor 30, to preventlifting or tearing of the conductor during the cutting stroke, as willappear more clearly hereinafter.

The shank 55 of a knurled-head clamping screw 56 passes freely throughan aperture 58 in the clamping bar 12 and similarly through a limitingmember or spacer 60 and is threaded into the base 10.

To operate the tool for cutting or shaving off a portion of a conductor30 on the panel 22, the panel is first placed in the tool between thebase 10 and jaw 36, as shown in phantom view in FIG. 2, and locatedtransversely of the tool by positioning appropriate ones of its knifecontacts 28 in the slots 24, the stop gauge 26 having been previouslyset to locate the edge 22' of the panel to bring the particularconductor 30 directly beneath the jaw faces 54. Clamping screw 56 isnext tightened causing the free portion of the base 16 to bend or springabout the reduced area portions 20 until first the panel 22 is clampedby jaw 36 and base It and then the spacer 60 next gripped between thebase 10 and clamping bar 12. In this position the jaw 36 will beexerting a predetermined clamping force on the conductor 39 and panel22, the force being determined by the particular height of the spacer66. The actuating arm 62 of the rock lever 16 is then pressed downwardlyto rock the cutting blade 14 thereby to sever and shave off a portion ofthe conductor 30 by cutting a discontinuity 31 therein (FIG. 6) andforming segment conductors 30. Since the cutting blade 14 has a curvedcutting stroke it will also shave a slight arcuate portion 62 (FIG. 5)from the panel 22, this portion not being shown in FIG. 6.

The slotted jaw 36 closely guides the cutting blade 14 to assure aclean, sharp and uniform cut while the jaw faces 54 act as hold-downs aswell as clamping faces to prevent tearing of the conductor adjacent tothe cut or lifting it from the panel.

The spacer 60 may be omitted if desired, however, it is preferable touse it to obtain a uniform clamping force, particularly when the tool isto be used by different operators.

While there has been disclosed a specific structure exemplary of theprinciples of the invention, it is to be understood that this is but oneembodiment thereof and that the invention may be constructed in avariety of shapes, sizes, and modifications without departing from thetrue spirit and scope thereof. Accordingly, it is to be understood thatthe invention is not to be limited by the specific tool disclosed butonly by the subjoined claims.

What is claimed is:

1. A tool for shaving off a portion of a printed circuit or the likeconductor on a face of a panel comprising, a rigid base, an elongatedrigid bar rigidly secured at one end to said base with its other freeend spaced therefrom, one of said base and bar members having aformation adjacent to its secured end whereby said base and said freeend are relatively movable elastically toward each other, a toothedcutting blade movably mounted on the free end of said bar, screwthreaded means operable independently of movement of said cutting bladefor eifecting relative movement between said base and said free end toclamp a said panel therebetween, and means for moving said cutting bladeacross a face of said panel while it is so clamped in such manner that atooth of said cutting blade will shave off a portion of a said conductorthereon.

2. A tool for shaving oif a portion of a printed circuit or the likeconductor on a face of a panel comprising, a rigid base, an elongatedrigid-bar rigidly secured at one end to said base with its other freeend spaced therefrom, one of said base and bar members having a reducedcrosssectional area adjacent to its secured end whereby said base andsaid free end are relatively movable elastically toward each other, atoothed cutting blade movably mounted on the free end of said bar, screwthread means manually operable independently of movement of said cuttingblade for effecting relative movement between said base and said freeend to clamp a said panel therebetween, means for limiting said movementto limit the clamping force on said panel, and means for moving saidcutting blade while said panel is clamped in such manner that a tooth ofsaid cutting blade will shave off a portion of a said conductor thereon.

3. A tool for shaving off a portion of a printed circuit or the likeconductor on a face of a panel comprising, a rigid elongated basemember, a rigid elongated bar member rigidly secured at one end to anend of said base member and the free ends of said members being spacedapart,

by said bar member for moving said cutting blade while said panel isclamped in such manner that a tooth of said cutting blade will shave offa portion of a said conductor thereon.

4. A tool for shaving off a portion of a printed circuit or the likeconductor on a face of a panel comprising, an elongated base member, anelongated bar member rigidly secured at one end to an end of said basemember, the free portion of one of said base and bar members beingmovable elastically relative to the free portion of the other member,the free portion of said bar member being provided with a jaw spacedapart from the free portion of said base member, a lever mounted on saidbar member, a toothed cutting blade guided by said jaw and actuated bymovement of said lever, and means for effecting relative flexingmovement between said jaw and said free portion of the base member torigidly clamp a said panel therebetween, a tooth of said cutting bladecutting a curved groove in said panel and shaving off a portion of asaid conductor thereon when said lever is moved.

5. A parting tool for severing or shaving off a portion of a printedcircuit or the like conductor on a face of a panel comprising, anelongated rigid base member, an elongated rigid bar member rigidlysecured at one end to an end of said base member, the free portion ofone of said members having a formation adjacent to its secured endmaking it flexibly movable toward the free portion of the other member,a jaw on the free portion of said bar member, a movable cutting bladecarried by said bar member and having a tooth with a cutting edgethereon movable longitudinally of said bar member when said blade ismoved, means for flexing said movable free portion of said one of saidmembers toward the free portion of the other member to rigidly clamp asaid panel between said jaw and said base member and to bring saidcutting edge into substantial contact with said panel, and meansoperable to move said cutting blade to project said cutting edge througha portion of said panel to sever and shave off a portion of a saidconductor thereon.

6. A parting tool according to claim 5 characterized further in thatsaid cutting blade is pivotally mounted on said bar member and said jawis slotted for guiding said cutting blade therein.

7. A parting tool according to claim 5 characterized further by theinclusion of gauge means on at least one of said members for locatingsaid panel in clamping position in at least one of two mutuallyperpendicular directions, said gauge means including a slotted surfacehaving at least one slot for receiving an associated element connectedto said panel and further including an adjustably mounted gauge on alateral side of said base member and settable in a direction parallel tothe direction of said slot.

8. A tool according to claim 3 wherein said one of said members having areduced cross-sectional area is said base member and said reducedcross-sectional area is formed thereon by at least one cross-slotextending through the major portion of the thickness of said basemember.

References Cited in the file of this patent UNITED STATES PATENTS964,182 Porter July 12, 1910 2,606,613 Junkunc Aug. 12, 1952 2,611,434Mugler Sept. 23, 1952 2,948,177 Arvidson Aug. 9, 1960

1. A TOOL FOR SHAVING OFF A PORTION OF A PRINTED CIRCUIT OR THE LIKECONDUCTOR ON A FACE OF A PANEL COMPRISING, A RIGID BASE, AN ELONGATEDRIGID BAR RIGIDLY SECURED AT ONE END TO SAID BASE WITH ITS OTHER FREEEND SPACED THEREFROM, ONE OF SAID BASE AND BAR MEMBERS HAVING AFORMATION ADJACENT TO ITS SECURED END WHEREBY SAID BASE AND SAID FREEEND ARE RELATIVELY MOVABLE ELASTICALLY TOWARD EACH OTHER, A TOOTHEDCUTTING BLADE MOVABLY MOUNTED ON THE FREE END OF SAID BAR, SCREWTHREADED MEANS OPERABLE INDEPENDENTLY OF MOVEMENT OF SAID CUTTING BLADEFOR EFFECTING RELATIVE MOVEMENT BETWEEN SAID BASE AND SAID FREE END TOCLAMP A SAID PANEL THEREBETWEEN, AND MEANS FOR MOVING SAID CUTTING BLADEACROSS A FACE OF SAID PANEL WHILE IT IS SO CLAMPED IN SUCH MANNER THAT ATOOTH OF SAID CUTTING BLADE WILL SHAVE OFF A PORTION OF A SAID CONDUCTORTHEREON.